Implementations this specification provide a method and an apparatus for determining data processing model parameters through multiparty cooperation. An example method performed by a data party device includes secretly sharing a first product with a cooperation partner device, based on characteristic data and a share of an original model parameter; communicating with the cooperation partner device, based on the share of the first product and a garbled circuit corresponding to an activation function, to obtain a share of a value of the activation function; secretly sharing a gradient of a loss function with the cooperation partner device, based on the characteristic data and the share of the value of the activation function, to obtain a share of the gradient of the loss function; and computing a share of a new model parameter.

A polynomial complete homomorphic encryption method based on the coefficient mapping transformation. A plaintext is expressed as a polynomial consisting of a set of random values, two sets of random coefficient factors and a random constant of a specified mapping function, and in the polynomial: the expression and a set of random coefficient factors of the specified mapping function are taken as a key; another set of random coefficient factors, a set of random arguments and random constants of the mapping function are taken as the ciphertexts for homomorphic operations, so that the part of function key performs three different mappings and then undergoes numerical fitting to obtain the family of operational support functions consisting of three sub-functions respectively, which are used to perform the homomorphic operation of the ciphertext based on the family of operational support functions and return to the locality for decryption by the key.

The present disclosure relates to exchanging data for multi-party computation. In some aspects, a server generates a first random number set, a second random number set, a third random number set, and a fourth random number set based on a first random seed, a second random seed, a third random seed, and a fourth random seed, respectively. The sever generates a fifth random number set and a sixth random number set, respectively, based on the first random number set, the second random number set, the third random number set, and the fourth random number set. The random numbers in the random number sets satisfy a predetermined condition. The server sends the first random seed, the second random seed, and the fifth random number set to a first device. The server sends the third random seed, the fourth random seed, and the sixth random number set to a second device.

A method, system, and computer program product for performing strong desensitization of sensitive data within a garbled circuit includes: compiling a predetermined program into a first program, where the compiled first program is encoded in a form of a garbled circuit, and where the predetermined program runs on sensitive data; and executing the first program, where executing the first program includes: executing an analytics function using tokenized data with a first set of sensitive information and analytics data with a second set of sensitive information, where the tokenized data originated from a data provider and the analytics data originated from an analytics provider; and generating an output of the first program using a result of the analytics function, where the output contains desensitized data.

A method, system, and computer program product for performing strong desensitization of sensitive data within a garbled circuit includes: compiling a predetermined program into a first program, where the compiled first program is encoded in a form of a garbled circuit, and where the predetermined program runs on sensitive data; and executing the first program, where executing the first program includes: executing an analytics function using tokenized data with a first set of sensitive information and analytics data with a second set of sensitive information, where the tokenized data originated from a data provider and the analytics data originated from an analytics provider; and generating an output of the first program using a result of the analytics function, where the output contains desensitized data.

The subject matter discloses a method and a system for securely distributing a credential and encryption keys for physical devices. The system comprises a security server and a physical device. the physical device comprises a memory module configured to store a share of the credential, a communication module configured to exchange signals, and a processing module configured to execute calculations upon request received on a wireless manner via the communication module from the security server, the calculations are transmitted to the security server to execute a multi-party computation process. The multi-party computation process outputs two shares of the credential, a first share is stored in the physical device. The physical device does not have access to the credential.

The subject matter discloses a method for securing personal information, comprising securing the personal information stored on a data server using a cryptographic secret, said cryptographic secret is unique to a user, storing a first share of the cryptographic secret on a secret storage server communicating with the data server and a second share of the cryptographic secret on a computerized device controlled by the user, detecting a request from the data server to perform an action on the personal information, transmitting the request to the computerized device controlled by the user to use the second share of the cryptographic secret to decrypt the personal information, decrypting the personal information using the first share and the second share, without storing both the first share and the second share in a single device concurrently and performing the action on the personal information on the data server.

A computer implemented system for anonymous electronic verification of location credentials including at least one processor and data storage is described in various embodiments. The system includes cryptographic mechanisms and electronic communication between one or more computing systems that in concert, provide verification of a prover's location credentials in accordance to logical conditions of a verifier's policy without providing additional information to a verifier entity.

A combination of secure texts of values a, b and c having a relationship c=ab is efficiently generated. A secure text generation part 12 generates secure texts [x.sub.i] of x.sub.i satisfying x.sub.i=f(k.sub.i), and secure texts [y.sub.i] of y.sub.i satisfying y.sub.i=g(k.sub.i), for i=0, . . . , m. A fragment generation part 13 generates .sub.i decrypted from [x.sub.i][a.sub.i] and .sub.i decrypted from [y.sub.i][b.sub.i], for i=1, . . . , m, and calculates [c.sub.i]+.sub.i[b.sub.i]+.sub.i[a.sub.i]+.sub.i.sub.i and generates secure texts [z.sub.1], . . . , [z.sub.m]; and A random number synthesizing part 14 generates a secure text [z.sub.0] using different values k.sub.0, . . . , k.sub.m and secure texts [z.sub.1], . . . , [z.sub.m].

Described are a system and computer program product for secure n-party computation. The system includes a computing device programmed or configured to communicate an input to a trusted execution environment (TEE), and receive a first encrypted output. The computing device is also programmed or configured to post the first encrypted output on a blockchain and receive a first proof of publication. The computing device is further programmed or configured to communicate the first proof of publication to the TEE and receive the first function output of the n-party computation. The computing device is further programmed or configured to communicate a witness to the TEE and receive a second encrypted output. The computing device is further programmed or configured to post the second encrypted output on the blockchain, receive a second proof of publication, communicate the second proof of publication to the TEE, and receive the second function output.